In going uphill it takes 2 hours 35 minutes. In coming down it takes 1 hour 25 minutes. I take rest in between for 15 minutes. When should I start, if I am to be back at the starting point by 2 PM?

Correct option is C

Given:

Time taken to go uphill = 2 hours 35 minutes

Time taken to come down = 1 hour 25 minutes

Rest time in between = 15 minutes

Must be back at starting point by 2:00 PM

Solution:

Uphill: $$2 \text{ h } 35 \text{ min} = 155 \text{ min}$$​​

Downhill: $$1 \text{ h } 25 \text{ min} = 85 \text{ min}$$​​

Rest: 15 min

Total time = 155 + 85 + 15 = 255 minutes

Convert back to hours:

255 min = 4 hours 15 minutes

Now subtract from 2:00 PM:

2:00 PM - 4 : 15 = 9 : 45 AM